Clinical characteristics of Mycoplasma pneumoniae pneumonia in Korean children during the recent 3 epidemics

PURPOSE: Mycoplasma pneumoniae (MP) is a major cause of community-acquired pneumonia in children. Since 2000, emerging macrolide-resistant MP has been reported. Three epidemics of MP pneumonia have occurred in Korea during the past 10 years: 2006–2007, 2011, and 2015. We investigated the differences in MP pneumonia of each epidemic in terms of clinical, laboratory, and radiologic perspectives. METHODS: We retrospectively analyzed 529 medical records of children (1–18 years of age) who were admitted and diagnosed with MP pneumonia at Kangbuk Samsung Hospital during the past 3 epidemic periods. We compared the clinical, laboratory, and radiologic characteristics of MP pneumonia among individual epidemics and between children younger and older than 6 years of age. RESULTS: The mean age of the patients was 5.7 years old, which had increased by each epidemic and showed the highest (6.3 years old) in 2015 compared to previous epidemics. Among 3 epidemics, there were no sex differences. The duration of fever after admission and hospitalization, and the percentage of lobar pneumonia and use of systemic steroids increased significantly in 2015 epidemic. Since 2006, the mean levels of erythrocyte sedimentation rate and lactate dehydrogenase had increased and in 2015 it marked the highest. Children older than 6 years showed a higher proportion of lobar pneumonia and pleural effusion as well as longer duration of fever (before and after admission) and hospitalization days than those younger than 6 years. CONCLUSION: This study suggests an increasing incidence of refractory MP pneumonia which required a more frequent use of systemic steroids over the past 10 years, and children older than 6 years were found to have more severe pneumonia than those younger than 6 years.

Risk factors for latent tuberculosis in children who had close contact to households with pulmonary tuberculosis

PURPOSE: Tuberculosis (TB) is a common and possibly fatal infectious disease, and its incidence and prevalence is quite high in Korea compared to other Organization for Economic Co-operation and Development countries. Patients who have active TB can cause latent tuberculosis infection (LTBI) in children, which may progress to reactivated tuberculosis. This study was performed to analyze the risk of adult TB that affects children's LTBI. METHODS: From June 2013 to May 2014, 60 children (32 boys, 28 girls) who came into close contact with adult patients diagnosed with pulmonary TB underwent LTBI tests. The children were divided into the 2 groups: the first group was finally diagnosed to LTBI, and the second group was proven not to have LTBI. We compared the risk of adult patients with pulmonary TB between children with LTBI and those without through a medical record review. RESULTS: The number of adult patients with TB was 36 (father 68%, mother 23%, grandparents 8%). The patients who came into close contact with the LTBI group were older (47.0±12.8 years vs. 41.3±6.6 years) and had higher erythrocyte sedimentation rate (ESR) levels than those of the second group. The rate of negative acid-fast-bacilli smear with positive culture results in patients who came into contact with the LBTI group was higher than in the second group. The cutoff value of ESR for the diagnosis of LTBI was 31 mm/hr with a sensitivity of 0.75 and a specificity of 0.85 (area under curve=0.748). CONCLUSION: Adult pulmonary TB patients who are older and have higher ESR levels may be risk factors for LTBI in children coming into close contact with them.